Along with the dramatic developments in semiconductor fabrication technologies and communication technologies during the last 20 years, researches and commercialization have been widely performed on lithium-ion batteries as power supplies for portable electronic devices, such as mobile communication terminals and laptop computers. Recently, to handle environmental problems including energy exhaustion and the greenhouse effect, demands for energy saving technologies are rapidly increasing. As a result, researches are actively performed on medium and large size batteries applicable not only to industries related to portable electronic devices, but also to electronic vehicles, hybrid vehicles, or power grids. As batteries for the purpose, nickel-metal hydride (Ni-MH) batteries and lithium secondary batteries are mainly researched. Here, since a lithium secondary battery utilizes lithium, which is the lightest metal with the lowest standard reduction potential from among known metals in nature, a battery with high energy density, high voltage, and high power output may be fabricated.
To embody such performance of a battery, it is important to develop a suitable current collector. It is necessary to enhance internal resistance and irreversibility of a current collector to improve performance of a battery. At the same time, it is necessary to secure high yield for economic feasibility of fabricating the current collector.